The only kind of Roleplay event I could see working is like the events that took place in Lord of the Rings Online.
You're not fighting things, you're not doing normal ingame activities, you're just... doing fun stuff. A horse race, a timed course around the region, getting drunk and navigating around with a hard to control character, etc.
ESO does have some of this in New Life, but it definitely needs more silly quests like that with a bit more depth to them.